Does the use of recombinant AAV2 in pulmonary gene therapy damage lung function?
ABSTRACT Forty-eight BALB/c mice were divided into two groups of 24 animals each. In the control group (CTRL) saline was intratracheally instilled, while the virus group (VR) received rAAV2-GFP (4 x 10(9) particles). These groups were subdivided into four sub-groups (n=6). Pulmonary mechanical parameters were analyzed after 3 weeks (VR1d3w) and at 1 (VR2d1w), 2 (VR2d2w) and 3 weeks (VR2d3w) after a second AAV2 dose. Fractions of the area of alveolar collapse and the amount of polymorpho- and mononuclear cells were determined by point-counting technique. Viral transduction was evaluated by immunohistochemistry. Lung mechanical data were similar in all groups. However, there was an increase in airway and lung parenchyma cellularity and in the fraction of area of alveolar collapse in the VR2d2w group, which nonetheless decreased with time. There was no evidence of apoptosis in any group. In conclusion, the gene transfer vector AAV2 induces, in the lung, a discrete inflammatory reaction that does not affect either baseline lung mechanics or airway hyperresponsiveness.
SourceAvailable from: Patricia Rieken Macedo Rocco[Show abstract] [Hide abstract]
ABSTRACT: Gene therapy is an alternative treatment for genetic lung disease, especially monogenic disorders such as cystic fibrosis. Cystic fibrosis is a severe autosomal recessive disease affecting one in 2500 live births in the white population, caused by mutation of the cystic fibrosis transmembrane conductance regulator (CFTR). The disease is classically characterized by pancreatic enzyme insufficiency, an increased concentration of chloride in sweat, and varying severity of chronic obstructive lung disease. Currently, the greatest challenge for gene therapy is finding an ideal vector to deliver the transgene (CFTR) to the affected organ (lung). Adeno-associated virus is the most promising viral vector system for the treatment of respiratory disease because it has natural tropism for airway epithelial cells and does not cause any human disease. This review focuses on the basic properties of adeno-associated virus and its use as a vector for cystic fibrosis gene therapy.Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas / Sociedade Brasileira de Biofisica ... [et al.] 09/2011; 44(11):1097-104. DOI:10.1590/S0100-879X2011007500123 · 1.08 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Background/Aims: Vectors derived from adeno-associated viruses (AAVs) are important gene delivery tools for treating pulmonary diseases. Phosphorylation of surface-exposed tyrosine residues from AAV2 capsid targets the viral particles for ubiquitination and proteasome-mediated degradation, and mutations of these tyrosine residues lead to highly efficient vector transduction in vitro and in vivo in different organs. We evaluated the pulmonary transduction efficiency of AAV8 vectors containing point mutations in surface-exposed capsid tyrosine residues. Methods: Male C57BL/6 mice (20-25 g, n=24) were randomly assigned into three groups: control group animals received intratracheal (i.t.) instillation of saline (50 μl), wild-type AAV8 group, and capsid mutant Y733F AAV8 group, which received (i.t.) AAV8 vectors containing the DNA sequence of enhanced green fluorescence protein (eGFP). Four weeks after instillation, lung mechanics and morphometry, vector transduction (immunohistochemistry and mRNA expression of eGFP), and inflammatory cytokines and growth factor expression were analyzed. Results: Tyrosine-mutant AAV8 vectors displayed significantly increased transduction efficiency in the lung compared with their wild-type counterparts. No significant differences were observed in lung mechanics and morphometry between experimental groups. There was no evidence of inflammatory response in any group. Conclusion: AAV8 vectors may be useful for new therapeutic strategies for the treatment of pulmonary diseases. © 2014 S. Karger AG, Basel.Cellular Physiology and Biochemistry 08/2014; 34(3):681-690. DOI:10.1159/000363033 · 3.55 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: This study investigated whether repeated administration of recombinant adeno-associated virus type 5 (rAAV5) to the airways induces inflammatory processes in the lungs of BALB/c-mice, with mechanical and histologic changes. Saline was instilled intratracheally in the control group, and rAAV5-green fluorescence protein (GFP) (4x10(11)particles) in the virus group (VR). These groups were subdivided into four subgroups: one dose analyzed 3 weeks later (VR1d3w) and two doses analyzed 1 (VR2d1w), 2 (VR2d2w) and 3 weeks (VR2d3w) after the second dose. Lung morphometry, mechanical parameters, airway responsiveness, rAAV5-GFP transduction and the expression of inflammatory cytokines were investigated. No significant differences in lung mechanics, airway responsiveness, and morphometry were observed. Re-administration of rAAV5 vector resulted in a decrease in GFP mRNA expression in the VR2d3w group. There was no evidence of inflammatory response or apoptosis in any group. rAAV5 did not induce an inflammatory process, mechanical or morphometric changes in the lungs. AAV5 may be an appropriate vector for lung gene therapy.Respiratory Physiology & Neurobiology 07/2009; 168(3):203-9. DOI:10.1016/j.resp.2009.06.016 · 1.97 Impact Factor